Dynamics of the Formation of the Phenolic Redox System of Coniferous Plants on the Example of Scots Pine (Pinus Sylvestris L.)

Objective: This study aims to investigation of the mechanisms of the redox processes in the formation of phenolic secondary metabolites in higher coniferous plants in natural growing places, using Scots pine as an example. Methods: The composition and reactivity of the phenolic fraction of the phenol-quinone redox system of the cell wall and the quantitative change of the pigment apparatus of pine needles during the growing season were investigated using a complex of physic-chemical methods (UV spectrophotometry, HPLC, redox-metry). Results and Discussion: It is shown that changes in the quantitative and qualitative composition of the phenolic compounds fraction that determine the redox state of the plant matrix occurs in plant tissue throughout the growing season. It is noted that dynamic self-regulation processes involving a complex consisting of phenolic compounds, pigments and enzymatic systems are a common pattern at all stages of plant development, ensuring that they perform protective functions of the photosynthetic apparatus of the needles of evergreen coniferous trees in boreal regions. The redox systems of the phenolic compounds are formed due to donor-acceptor interactions in photosystems I and II with participation of photosynthetic pigments. The implementation of the protective functionality of phenolic compounds of the pine tree greenery is enabled by high values of the effective oxidation potential (up to 780 mV) and the free energy of oxidation (–150 kJ/molOHph). Conclusions: This research provides new experimental data on the changes in the contents of phenolic secondary metabolites and the pigment complex of the needles during the growing season for coniferous plants, using the example of Scots pine (Pinus sylvestris).